This invention relates to a loading device for loading discrete yeast cakes, and particularly to a loading device for loading discrete yeast cakes into a container in such manner that the yeast cakes lie in uniform rows and columns and with the lower surfaces of the yeast cakes all lying flat against a generally planar bottom support surface of the box, without damage to corners or edges of the yeast cakes.
This yeast cake loading device may also be adapted for use as a loader for any regular, rectangular, prismatic solid discrete objects, for example, boxes containing any product, bricks, blocks, construction toy elements having regular rectangular prismatic shapes, regular rectangular prismatic elements used in assembly work for assembly into final products, as well as non-rectangular objects which have contact surfaces such that discrete rows can be defined along some line and which are stable against any vertical upward movement during operation of the loading device.
It is well-known to load regular rectangular prismatic articles into boxes in such as way as to achieve a densest packing arrangement. In this densest packing arrangement, the entire volume of a container is filled by abutting rows and columns of the regular rectangular prismatic solids. In the case of bricks, for example, uniform bricks are arranged side by side such that the lower surfaces on each brick in a particular level in the box lie generally along a given plane; adjacent bricks have contacting sides such that no gap is left between adjacent bricks. Such loading is commonly performed manually by workers at an assembly line having a conveyor belt or other arrangement for moving the product to be loaded into a larger receptacle. In another arrangement, complex devices are used to grasp an entire row or column of the discrete regular rectangular prismatic articles and bodily transport them as a single row or column into the receptacle. In a still further type of known device, machinery is used to transport the discrete regular rectangular prismatic articles already arranged in rows and columns and push the articles into an open carton or other receptacle without any change in elevation of the articles.
The prior art loading devices as described above, have several drawbacks. In the first type, it is the cost of the complex equipment used to perform the loading operation. The cost is both in the initial capital investment to acquire the equipment, as well as to keep the complex equipment maintained and to replace parts which wear out or are damaged. In addition, in physically transporting entire rows or columns of the product by applying force along opposing end surfaces of end articles of the respective rows or columns, the individual articles must be sufficiently strong in compression as to withstand the force applied necessary to keep the weight of the row or column from causing downward displacement of individual articles and thereby causing failure of the loading device. In particular, in the case of yeast cakes which are relatively weak in compression and tend to crumble, such a loading device is impractical.
The second type of loading device discussed above can in principle have a relatively simple arrangement of a conveyor belt, open receptacle, and a pusher rod for pushing an entire discrete set of rows and columns of the articles into the container. This is suitable in the case of relatively massive articles in which differences in the coefficients of friction along the underside of each individual article do not cause rotation of the articles since the articles have a relatively great inertia and the distance to be traveled is generally small. Such rotation, even a relatively small amount of rotation, of each individual article would cause a misalignment of at least an individual article thereby causing an interference between an upstanding sidewall of the container and the intended direction of travel of the article. This would result in a misfeed. Thus, in the case of a relatively very light article such as a yeast cake, slight misalignments could occur very easily, since yeast cakes have a relatively low inertia and would not tend to resist rotation as well as much heavier objects would. Furthermore, the success of the prior art loading device of this type requires that a preformed box having four connected sides and open bottom and top ends be employed. Therefore, if a container is desired to be employed which already has four upstanding sidewalls and a bottom already attached to the upstanding four sidewalls as well as an open top, the prior art loading devices would not be generally satisfactory. In particular, although this could be attempted using the prior art devices, in the case of yeast cakes, the shallowness of the box would hinder a vertical placement of a group of rows and columns of yeast cakes since upon retraction of the pusher rod, the forces of gravity and slight vibrations would tend to cause the yeast cakes to fall out of the relatively shallow container.
When it is desired to load articles having relatively shallow heights as compared to their widths and lengths, they cannot easily be handled using conventional equipment. Furthermore, when relatively delicate or crumbly articles are to be loaded, it is especially desirable that sudden forceful movements of the articles be avoided. Where it is desired to load a group of rows and columns of articles into an open container having upstanding side walls, sudden dropping of the articles is also to be avoided since this may result in tumbling of the articles thereby rendering them uneven and unsuitable for shipment, or it may result in deformation or crumbling of the articles due to their low compressive strength. Typical of the loading devices for handling bricks using relatively complex equipment is the type disclosed by Brown, Jr., in U.S. Pat. No. 3,669,283.
Brown discloses a method and apparatus for dehacking brick, in which brick stacked in courses of doublelayer rows are dehacked by sequentially removing complete successive courses from each stack. Successive double-layer rows are removed simultaneously from each pair of courses in the upper layer of each such unit is aligned with a lower unit to form a single-layer line of bricks all having their face sides facing outwardly. A kiln car is used to move stacked courses and rows of bricks toward a car unloading means which has a course-gripping head. A hydraulic ram loads courses, deposited upon input conveyor 14, onto one or the other of conveyors 18,18'. Two pusher assemblies 24,24' are employed for moving the courses loaded by the ram 22 onto conveyors 18,18'. The courses are received by a discharge platform 26, and two row-clamping assemblies 28,30 are sequentially engageable with the bricks deposited on platform 26. However, at no time is a course of bricks moved other than as a unit; for example, no bricks of a course are tilted with respect to other bricks so that a gentle, orderly drop occurs in elevation between a given brick in a course and any other given brick in a course.
Other types of discrete-article handling devices are those employing a simpler arrangement of equipment, especially including a ram which is selectively actuated to move articles from one position to another. The articles may be either stacked or in the alternative, organized in rows or columns. Typical of such prior art devices is that to Langen in U.S. Pat. No. 3,923,l44; Jones in U.S. Pat. No. 3,837,466; Joa in U.S. Pat. No. 4,141,193; and Bernham, et al in U.S. Pat. No. 4,214,655.
Langen discloses an intermittent load accumulator having a carton loader mechanism 62 which acts as a ram to load accumulated cartons 64 into loading cartons 65. The hydraulic cylinder 68 is used to move an end load pusher 66 reciprocally. In operation, an endless stream of cartons is fed from a conveyor belt moving transverse to the direction of operation of the pusher 66 onto a conveyor belt moving parallel to the direction of pusher 66. A pusher bar 40 having pusher segments 42 pushes accumulated cartons in a direction transverse to the direction of movement of pusher 66 so as to push selected numbers of cartons in front of the pusher 66. The pusher 66 then pushes the predetermined number of cartons into a receptacle 65 which in this case is a cardboard box having open bottom and top ends. However, no verticle drop of any of the selected predetermined number of cartons is employed in the loading operation. Furthermore, a carton having a closed bottom, four upstanding side walls and an open top cannot be used in this arrangement. Furthermore, very light objects such as yeast cakes would tend to be disturbed slightly during all of the pushing operations discussed in the above, and any slight rotation of the yeast cake would prevent a satisfactory loading operation from occurring since the entranceway into the box is severely constrained in the Langen patent.
Jones teaches a brick-handling apparatus in which layers of bricks are stacked into orderly rows and columns of brick. A pusher member 70 is actuated by an air cylinder 72 and operates to move the grouped rows and columns of bricks back to the rear of a platform 50 to make room for other groups of bricks to be removed. Another pusher member 104 is disclosed and is also actuated by an air cylinder. These pushers are generally operated transversely to the main path of conveyance of the bricks. As in the above, there is no teaching of loading a group of bricks such that a difference in elevation exists between a given selected one of the group of bricks and any other selected one of the group of bricks such that a particular one of the bricks is loaded first by being moved through a vertical drop into a receptacle while others of the bricks have not been moved through such a drop completely. Joa discloses a horizontal diaper grouper wherein stacked pads are tipped on end and two stacks are grouped together in a horizontal row or group of pads with the group discharged as a unit into a shipping container. Here, the pusher member actually is a horizontal support for the stacks in one position and bodily moves the stacks through an arc such that the pusher becomes a vertically-oriented member. A horizontal pusher plate 90 having a power cylinder 92 is used to discharge two stacks 14 through a loading funnel 87. A receptacle is employed to receive the stacks having open flaps such that a single side of the box-like receptacle is open. However, as with the above-discussed references, the stacked articles are not moved through a vertical distance into a receptacle having an open top.
Bernham et al teaches an article-handling apparatus especially useful for handling concrete blocks. The concrete blocks are lifted so as to invert them. The blocks are moved about in a group along conveyor belts. A block transfer arm can pivot to a horizontal position over the blocks to pick up the blocks without interference. A block gripping system is shown in FIG. 3 having three steel shoes which are fitted into recesses on each side of the transfer arm 24. A pivotal transfer motion is used. However, as in the above-discussed references, no vertically-downward displacement of any of a selected one of a group of articles to be transferred occurs. In particular, in Bernham et al, the bricks are moved as a single unit and are not loaded into a receptacle having a vertically-downward drop.